With the construction of the 3rd generation mobile communication (3G) of China is developed progressively, all three major mobile communication operators step into the 3G era formally. However, since in the initial stage of the construction of the current 3G network and the following development period, the cover level of the 3G network, compared with the 2nd Generation mobile communication (2G) network which is already optimized and improved constantly in more than ten years, no matter the cover breadth (the 2G network nearly covers all natural villages of our country) or the cover depth (such as, indoor, basement and subway, etc.) is greatly fallen behind, therefore, each major operator regards, invariably, the long-term dual network co-existence of the 2G and the 3G as its own operation target and strategy. China Mobile has proposed correspondingly the three “No” principle “No card changing, No number changing, No requirement of registration” and the singularly-colored Time Division-Synchronization Code Division Multiple Access (TD-SCDMA)/Global system for Mobile Communications (GSM) dual mode and single standby customized cell phone terminal to popularize and run its own TD-SCDMA 3G network.
But this kind of strategy, “co-existence of the 2G and 3G network” and “TD-SCDMA/GSM dual mode and single standby customized terminal”, meets difficult problem in the real operation. On one hand, due to the existing strategy of “2G and 3G dual mode handover”, the reselection of the cell phone terminal is frequent, the power consumption is serious, the conversation is dropped, the network stream is cutoff, and even the abnormal faults take place occasionally such as the network disconnecting, etc. so that the user experiences is worse; on the other hand, due to the cover quality of the existing 3G network is still not so good as the GSM network, customers have little confidence in the TD-SCDMA network. The problem of the network has caused the predicament of the terminal, and the predicament of the terminal has enlarged the problem of the network conversely.